wifi: iwlwifi: mld: fix NAN max channel switch time unit

wifi: iwlwifi: mld: fix NAN max channel switch time unit

The max_channel_switch_time in wiphy_nan_capa is in microseconds, but
the value was set to 4, which is only 4 microseconds instead of the
intended 4 milliseconds.

Fix by using 4 * USEC_PER_MSEC.

Signed-off-by: Israel Kozitz <israel.kozitz@intel.com>
Reviewed-by: Ilan Peer <ilan.peer@intel.com>
Link: https://patch.msgid.link/20260510234534.cb3c05e5d334.I89d9f336aaf388c6e48769de5fe1e5db19295057@changeid
Signed-off-by: Miri Korenblit <miriam.rachel.korenblit@intel.com>